? The Nikolsky sign ? a firm sliding pressure with the finger separates
normal-looking epidermis from dermis, producing an erosion; also
--- Content provided by FirstRanker.com ---
seen in TEN
? Bulla-spread phenomenon - gentle pressure on an intact bulla forces
--- Content provided by FirstRanker.com ---
the fluid to spread under the skin away from the site of pressure (alsok/a Asboe?Hansen sign, or the "indirect Nikolsky" or "Nikolsky II"
sign)
--- Content provided by FirstRanker.com ---
Casal's necklace (Pellagra dermatitis)? Development of sharply demarcated area of erythema on dorsa of
hands, wrists, forearms, the face & V of the neck (photoexposed parts
--- Content provided by FirstRanker.com ---
of the skin)
? F/B well-demarcated area of pigmentation
? The sharply demarcated lesions on the neck & upper central part of
--- Content provided by FirstRanker.com ---
the chest - known as Casal's necklace
NF1
--- Content provided by FirstRanker.com ---
? Button hole sign: Molluscum fibrosum - Small, superficial, soft, skin-colored to darker, dome-shaped nodules, which can be pushed
through a defect in the skin
--- Content provided by FirstRanker.com ---
? The Crowe sign- Pathognomonic presence of axillary freckling in NF1? Present in about 30% cases
Carpet tack sign (DLE)
--- Content provided by FirstRanker.com ---
? Characteristic lesion is a well-demarcated, discoid/annular,erythematous plaque with adherent scales
? When the scale is removed, its undersurface shows keratotic spikes
--- Content provided by FirstRanker.com ---
which have occupied the dilated pilosebaceous canals
Dermatomyositis
? Dermatomyositis ? Characterized by autoimmune inflammatory injury
--- Content provided by FirstRanker.com ---
to striated muscle & skin
? Heliotrope (a lilac-colored flower) erythema: Faint lilac erythema,
--- Content provided by FirstRanker.com ---
periorbitally, usually associated with edema? Gottron's papules: Violaceous, atrophic papules over the knuckles &
pressure points
--- Content provided by FirstRanker.com ---
? Gottron's sign: Symmetrical, lilac erythema & edema over
interphalangeal or metacarpophalangeal joints, elbows & knees
--- Content provided by FirstRanker.com ---
? Shawl sign: Symmetrical confluent violaceous erythema extendingfrom dorsolateral aspect of hands, forearms & arms to deltoid region,
shoulders & neck
--- Content provided by FirstRanker.com ---
? Mechanic's hand: Confluent symmetric hyperkeratosis along ulnar
aspect of thumb & radial aspect of fingers
Psoriasis
--- Content provided by FirstRanker.com ---
? Grattage test - Scales in a psoriatic plaque can be accentuated by
grating with a glass slide
--- Content provided by FirstRanker.com ---
? Auspitz sign- 3 steps? Step A: Gently scrape lesion with a glass slide - This accentuates the
silvery scales (Grattage test positive). Scrape off all the scales
--- Content provided by FirstRanker.com ---
? Step B: Continue to scrape the lesion ? A glistening white adherentmembrane (Burkley's membrane) appears
? Step C: On removing the membrane, punctate bleeding points
--- Content provided by FirstRanker.com ---
become visible - positive Auspitz sign
Leprosy (Hansen's disease)
--- Content provided by FirstRanker.com ---
? Cardinal signsA case of leprosy is a person having one or more of the following three
cardinal signs & who has yet to complete a full course of treatment:
? Hypopigmented or reddish skin lesion(s) with definite
--- Content provided by FirstRanker.com ---
loss/impairment of sensations
? Involvement of the peripheral nerves, as demonstrated by definite
--- Content provided by FirstRanker.com ---
thickening with loss of sensation in the area of distribution? Positive skin smear for acid - fast bacilli
`Groove sign' of Greenblatt
--- Content provided by FirstRanker.com ---
? Inguinal syndrome (secondary stage) of lymphogranuloma venereum? Enlargement of the femoral & inguinal lymph nodes separated by the
inguinal ligament
--- Content provided by FirstRanker.com ---
Homan's sign (DVT)? When symptomatic, onset of DVT is usually acute with swelling, pain
& cyanosis
--- Content provided by FirstRanker.com ---
? Pain worsens on dorsiflexion of foot
Photodermatology
? Electromagnetic radiation: any kind of radiation consisting of
--- Content provided by FirstRanker.com ---
alternating electric and magnetic fields and which can be propagated
even in the vacuum
--- Content provided by FirstRanker.com ---
? Solar spectrum consists of electromagnetic (EM) radiations extendingfrom
?Very short wavelength cosmic rays
--- Content provided by FirstRanker.com ---
?X-rays & -rays?Ultraviolet
?Visible
?Infrared radiation
?Long (wavelength) radio and television waves
--- Content provided by FirstRanker.com ---
UV, Visible & Infrared light
? Light having wavelength b/w 200 - 400 nm ? ultraviolet radiation
--- Content provided by FirstRanker.com ---
(UVR); classified as:? UVC (200?290 nm): does not reach Earth's surface as it is filtered by
the ozone layer of the atmosphere
--- Content provided by FirstRanker.com ---
? UVB (290?320 nm): 0.5% of solar radiation reaching Earth's surface;
reaches only up to the epidermis; causes sunburn; does not pass
--- Content provided by FirstRanker.com ---
ordinary glass? UVA (320?400 nm): 95% of solar radiation reaching Earth's surface;
penetrates both epidermis and dermis; causes photoaging & tanning
--- Content provided by FirstRanker.com ---
of the skin; passes through ordinary window glass
? Visible light: Extends between 400 and 700 nm; is part of EM
spectrum perceived by eyes
--- Content provided by FirstRanker.com ---
? Infrared radiation: Extends beyond 700 nm; is responsible for heating
effect
--- Content provided by FirstRanker.com ---
Sunburn? Etiology: Action spectrum: UVB which induces release of cytokines in
skin, resulting in pain, redness, erythema edema and even blistering
--- Content provided by FirstRanker.com ---
? Skin type: Most frequent and intense in individuals who are skin type
I & II
--- Content provided by FirstRanker.com ---
? Clinical features? Seen in light skinned
? Areas overexposed to UVR become painful and deeply erythematous
--- Content provided by FirstRanker.com ---
after several hours
? Redness peaks at 24 h and subsides over next 48?72 h, followed by
--- Content provided by FirstRanker.com ---
sheet-like peeling of skin and then hyperpigmentationTreatment
? Prevention
--- Content provided by FirstRanker.com ---
? Avoiding overexposure to sun (e.g., sunbathing), especial y by light-skinnedindividuals
? Using protective clothing and sun shades
--- Content provided by FirstRanker.com ---
? UVB protective sunscreens
? Symptomatic treatment
--- Content provided by FirstRanker.com ---
? Calamine lotion provides comfort? Topical steroids help, if used early
? Nonsteroidal anti-inflammatory drugs like aspirin relieve pain & also the
--- Content provided by FirstRanker.com ---
inflammation
Tanning
--- Content provided by FirstRanker.com ---
? Etiology: Fol owing exposure to UVR, pigmentation occurs in two phases:? Immediate pigmentation: Occurs within 5 min of exposure to UVA and is
due to:
--- Content provided by FirstRanker.com ---
?Photo-oxidation of already formed melanin
?Rearrangement of melanosomes
--- Content provided by FirstRanker.com ---
? Delayed pigmentation: Begins about 24 h after exposure to both UVB aswel as UVA; due to:
?Proliferation of melanocytes
--- Content provided by FirstRanker.com ---
?Increased activity of enzymes in melanocytes resulting in increased
production of melanosomes
--- Content provided by FirstRanker.com ---
?Increased transfer of newly formed melanosomes to adjoiningkeratinocytes
? Clinical features
? Pigmentation following exposure to light occurs in two phases:
--- Content provided by FirstRanker.com ---
? Immediate pigmentation lasts for about 15 min? Delayed pigmentation lasts for several days
? Degree of pigmentation depends on the constitutional skin color
? Lighter skins burn on UV exposure while darker skins tan
--- Content provided by FirstRanker.com ---
Photoaging? Etiology
? Photoaging involves changes in epidermis and dermis
? Action spectrum: Epidermis is affected primarily by UVB and dermis
--- Content provided by FirstRanker.com ---
by both UVA and UVB
? Manifestations
? Photoaged skin appears dry, deeply wrinkled, leathery and irregularly
--- Content provided by FirstRanker.com ---
pigmented
? Comedones are present, especially around the eyes
? Histologically: marked elastotic degeneration
--- Content provided by FirstRanker.com ---
Polymorphic Light Eruption (PMLE)? Etiology
? Action spectrum: UVA (more frequently incriminated) or UVB (less
--- Content provided by FirstRanker.com ---
frequently)? Probably a delayed hypersensitivity to a neoantigen produced by the
action of UVR on an endogenous antigen
--- Content provided by FirstRanker.com ---
? Epidemiology
? Prevalence: Fairly common dermatosis
? Gender: Female preponderance
? Age: Usually in third to fourth decade
--- Content provided by FirstRanker.com ---
Clinical features
? Described as polymorphic eruption, but in a given patient lesions are usually
--- Content provided by FirstRanker.com ---
monomorphic? Small, itchy, papules, papulovesicles or eczematous plaques on an erythematous
background
--- Content provided by FirstRanker.com ---
? Develop 2 h to 2 days after exposure to UVR
? Sites of predilection
--- Content provided by FirstRanker.com ---
? Most frequently seen on the sun-exposed areas:? Dorsae of hands, nape of neck, `V' of chest and dorsolateral aspect of forearms
? Face and covered parts are occasionally involved
--- Content provided by FirstRanker.com ---
? Course
? Recurrent problem, begins in spring and persists through summer
Treatment
--- Content provided by FirstRanker.com ---
? Photoprotection:
? Avoid exposure to sunlight
--- Content provided by FirstRanker.com ---
? Use of appropriate clothing? Sunscreens: Important to use UVA sunscreens (i.e., inorganic sunscreens.
Or those containing benzophenones, avobenzone, tinosorb, etc.)
--- Content provided by FirstRanker.com ---
? Symptomatic treatment:
? Topical/systemic steroids, depending on severity
--- Content provided by FirstRanker.com ---
? Antihistamines? Hardening of skin: With gradual y increasing doses of UVB or PUVA
? Unremitting PMLE: Azathioprine, thalidomide and cyclosporine are useful
--- Content provided by FirstRanker.com ---
? Phototoxic
? Reaction- Non-immunological
? In all individuals exposed to chemical and light in adequate dose
? Photoallergic
--- Content provided by FirstRanker.com ---
? Reaction- Immunological response? To a photoproduct created from chemical by light
? Occurs in sensitized individuals
? Clinical features
? Phototoxic reactions
--- Content provided by FirstRanker.com ---
? Dose of drug/chemical needed: Large? Latent period: Reaction immediate (within minutes to hours) after
exposure to light and can occur after first exposure
--- Content provided by FirstRanker.com ---
? Morphology: Initially, there is erythema, edema, and vesiculation? F/B desquamation and peeling
? Finally the lesions heal with hyperpigmentation (similar to sunburn).
? Photoallergic reactions
--- Content provided by FirstRanker.com ---
? Dose of drug/chemical needed: Small? Latent period: Reaction occurs on second or third day
? Does not occur on first exposure but after second or later exposures
? Symptoms: Itching often severe. Aggravated after sun exposure
? Morphology: Photoallergic reactions are similar to phototoxic
--- Content provided by FirstRanker.com ---
reactions but are more eczematous
? Investigations
? Phototoxic reactions
? No investigations required
--- Content provided by FirstRanker.com ---
? Photoallergic reactions? Photopatch tests
Treatment
? Phototoxic reactions
--- Content provided by FirstRanker.com ---
? Photoprotection? Withdrawal of drug: Only necessary, if excessive exposure to UVR cannot be avoided
? Symptomatic treatment:
? Topical steroids
? Nonsteroidal anti-inflammatory drugs
--- Content provided by FirstRanker.com ---
? Photoal ergic reactions? Photoprotection: Very important
? Withdrawal of drug & substitution with a chemical y unrelated drug is essential
? Symptomatic treatment:
? Mild disease: Topical steroids and antihistamines
--- Content provided by FirstRanker.com ---
? Severe disease: Systemic steroids, azathioprine & methotrexate in severe dermatosis? Solar radiation can be both a `boon' or `bane' to the skin
Thank you
--- Content provided by FirstRanker.com ---